rbutil: added builtin rbspeex encoder. Reworked encoder configuration.
tree1247110323388df365c80da86063d75b5a438eb3
drwxr-xr-x - apps
drwxr-xr-x - bootloader
drwxr-xr-x - docs
drwxr-xr-x - firmware
drwxr-xr-x - flash
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